2015.02.24

A big part of the work I do is the process, and trying to find tools that fit the way I work, and are also available. “Available” may mean open source, or free (as it beer) or multi-platform, or some other criteria I come up with.

In my Digital Craft class we’ve used RhinoCAM to generate the G-code needed to run the 4×8 CNC router in the DCRL. RhinoCAM has a lot of options, as it should for a full-on commercial package. Meanwhile, I’ve been working on a Shapeoko2, which is a small and affordable hobby-level CNC machine. For a machine like this, I’d like to use a workflow that doesn’t require expensive commercial software, because at some point I may not have access to Rhino and I’ll need tools I can afford.

(I should note that I have used CamBam in the past, but being commercial software that is Windows-only doesn’t entice me to want to use it again.)

I’ve played a little bit with Easel from our friends at Inventables, but I’m also not a fan of hosted solutions that can disappear, or start charging for access, etc. At this point I start to sound extremely picky, but really, I’m just looking for tools I can rely on, that are not expensive, and run on the platforms I use. (Easel is actually really nice, and while it’s easy to use, I think that comes at the price of hiding some of the complexity and advanced features I want to learn. Still, if you just want to cut/carve/engrave, check it out.)

I stumbled up MakerCAM, and there’s a bunch more info about it on the Shapeoko wiki. Basically it’s a Flash application (!) that you can use online, or download and run offline, which provides all the basic needs of a CAM application. And it actually works.

I started as I often do, drawing a 2D vector file in Inkscape. (Oh, I should mention there is an extension for Inkscape called Gcodetools, but we’ll skip that for now.) Once I had my Inkscape file I saved it as an SVG, as you normally would with Inkscape.

I then loaded the SVG into MakerCAM. Note that if you load an SVG from Inkscape you need to set the px/inch to 90 in the preferences. Once in MakerCAM it’s fairly easy to create the toolpaths and generate the G-code. If in doubt, check out the help page and the tutorial page for all the info.

After exporting my G-code file I was able to load it into the Grbl Controller and run it on the Shapeoko. Now, Grbl Controller is no Mach3, but it’s also open source, and multi-platform, so there’s that. (Yes, I know the image above does not match the first two images, that’s because I went crazy with the hatch fill from the Egg-Bot extension for Inkscape. Just pretend you know what I’m talking about.)

Oh, if you want to “run” your G-code before you run your G-code to make sure it’s doing what you think it’s doing, check out OpenSCAM, which is a nice little simulator.

(And yes, I know of Chilipeppr for Grbl, but I’ve not dug into it yet.)